In a classic episode of Dexter's Laboratory, the boy genius inventor Dexter rigs up a machine to help him learn French while he sleeps. But the machine breaks and simply repeats "omlette du fromage" over and over, which means poor Dexter wakes up being able do nothing but order a cheese omelet in French. Hilarity ensues.

Sleep learning, the idea that we could learn things while we slumber, isn't new. But new research suggests that the science-fiction staple (it's found in everything from Brave New World, to Fahrenehit 451, to A Clockwork Orange to Starship Troopers) it might actually be possible. Researchers at the Weismann Institute presented sleeping people with odors and tones. When those people woke up, they would start sniffing when they heard the tone, even when there was no odor. The press release explains:

In the experiments, the subjects slept in a special lab while their sleep state was continuously monitored. (Waking up during the conditioning – even for a moment – disqualified the results.) As they slept, a tone was played, followed by an odor – either pleasant or unpleasant. Then another tone was played, followed by an odor at the opposite end of the pleasantness scale. Over the course of the night, the associations were partially reinforced, so that the subject was exposed to just the tones as well. The sleeping volunteers reacted to the tones alone as if the associated odor were still present – by either sniffing deeply or taking shallow breaths.

Thusfar, sleep learning has yet to actually teach anyone anything. While we now know that our brains consolidate information garnered during the day, actually teaching sleeping people new things has never been done. Lead author Anat Arzi told the New York Times, "The common knowledge is that you cannot learn new information while you’re asleep, even though your brain is able to do so many other things while you are asleep." She added, "We need to understand where the border lies between what we can and what we cannot learn in sleep."

So before you rig up a Dexter's lab style sleep learning contraption, you might want to wait for science to show that sleep learning is even possible.

Contributing Editor
Rose Eveleth is a freelance writer, producer and designer based in Brooklyn, New York. Her work has appeared in Scientific American, OnEarth, Discover, New York Times, Story Collider and Radiolab. She holds degrees from the University of California, San Diego and New York University.
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